Ball bearing and retaining band locking device for the outer sleeve of adjustable chokes



2,866,288 INING BAND LOCKING DEVICE FOR Dec. 30, 1958 5. L.'HERTER BALL BEARING AND RETA THE OUTER SLEEVE 0F ADJUSTABLE CHOKES Filed Sept. 15, 1952 R Z Ni H BY M I U. I M 4 Annual:

Unite George L. Herter, Waseca, Minn., assignor to Herters, Inc., Waseca, Minn, a corporation of Minnesota Application September 15, 1952, Serial No. 309,621

1 Claim. (Cl. 42-79) This invention relates generally to gun chokes and particularly to the locking mechanism for etaining the choke sleeve in adjusted rotated position.

It has long been a problem to provide suitable holding means for retaining the restricting sleeve of an adjustable gun choke in the desired restricting position. The spring hook member previously used in all controllable gun chokes and similar to that disclosed in my co-pending application, Serial No. 188,307, filed October4, 1950, now abandoned, required the use of relatively wide spaced longitudinal slits between the choke jaw segments and of course these wide slits engage the shot as it passes therethrough and cause deflections thereof which produce substantial irregularities in the shot pattern discharged from the gun. It is obvious that, if narrower slits were used with the conventional type of retaining hook, the slit engaging end of said hook would have to be reduced in width and thus, when engaged in a slit, would be extremely difficult to remove therefrom by merely rotating the outer sleeve. Therefore, relatively wide slits and blunt end retaining hook elements are required with conventional adjustable chokes.

It is an object of this present invention to provide a novel and greatly improved sleeve locking mechanism which requires only relatively narrow slits to be formed in the choke jaw but positively positions the adjusting sleeve, thus producing a uniform undistorted pattern of shot discharged therethrough.

It is another object to provide a choke sleeve having a tapered interior choke jaw formed from a plurality of separate segments divided by narrow slits formed therein, said sleeve having at least one spring pressed ball mounted in an aperture therethrough and adapted to securely hold said sleeve in adjusted rotated position.

More specifically, it is an object of this invention to provide a locking mechanism for a gun choke sleeve consisting in a spring band mounted in a circumferential groove around the outer portion of said sleeve which has at least one ball receiving aperture formed therethrough within which a ball is adapted to be rotatably mounted and said spring bank having a concave ball receiving recess formed in the underside thereof in opposed relation to said aperture and resiliently holding said ball in said aperture to resiliently urge said ball against the outer surface of the segmented choke jaw structure to permit said ball to be received in a selected slit to hold the sleeve in the desired adjusted position.

Still more specifically, it is an object to provide a locking mechanism for adjustable gun chokes having a plurality of circumferentially spaced relatively small diameter spring pressed balls adapted to be received in selected extremely narrow slits formed between the segments of the choke jaws to positively hold the choke in adjusted position but, due to the rotatability of the balls, with their respective apertures, permitting the relatively easy adjustment of the choke sleeve in both directions.

These and other objects and advantages of this invention will more fully appear from the following description made in connection with the accompanying drawings wherein like reference characters refer to the same or similar parts throughout the several views and in which:

Fig. 1 is a side elevational view of this invention showing the same mounted on the forward end of a gun barrel; Fig. 2 is a horizontal sectional view taken substantially along the line 2-2 of Fig. 1;

Fig. 3 is a transverse vertical sectional view taken substantially along the line 3-3 of Fig. 1.

As illustrated in the accompanying drawings, the forward end portion of a gun barrel 6 is shown having a variable choke 7 fixed at the discharge end thereof. The gun sight 8 is mounted on the rear portion of said choke 7. The choke 7 is of a generally similar design to the variable choke described in the co-pending application previously identified herein and has an inner tubular member 9 with a plurality of longitudinally extending slits or slots 10 formed in the forward discharge portion thereof and producing a plurality of yieldable choke jaw segments 11 therebetween. The slits 10 are relatively narrow through out their entire length and are only of sufficient width to permit the necessary reduction in bore diameter for choking purposes. The outer portion of each of said segments is tapered in a conventional manner and an outer sleeve 12 is threadably mounted on said inner tubular member 9 and has a camming surface 12a of gradually decreasing diameter toward the outer end thereof for engagement with the tapered end portions of the segments 11 to produce a choking action by camming said segments inwardly when the sleeve 12 is shifted rearwardly on the inner tubular member 9.

This present invention consists in the mechanism for holding the sleeve 12 in adjusted rotated position. The sleeve 12 has a transverse peripheral groove 13 formed in the outer intermediate portion thereof and a plurality of peripherally spaced ball receiving apertures 14 are formed through the side wall of the sleeve at the bottom of said groove 13. A resilient split ball retaining band 15 is mounted in said groove 13 and has an outwardly extending concave recess 15a formed in an intermediate portion thereof for respectively retaining a plurality of relatively small balls 16 in said apertures 14. The split ends of ball retaining band 15 may be securely fastened as by anchoring the same together or by connecting said ends to the adjacent portions of the groove 13. This, however, has been found to be unnecessary if the band 15 has sulfieient tension therein to securely hold the balls 16 in said apertures and press the same tightly against the adjacent outer surface of one of the segments 11. The halls are of sufiiciently small diameter to be tightly received in even the relatively narrow slits 10 to securely hold the outer slees e 12 in the desired rotated position. However, said balls are also permitted to rotate sufiiciently to prevent the same from becoming locked in said slits and permit rotation of said sleeve in both directions without undue force being applied thereto.

The operation of this invention is generally similar to that of the choke disclosed in the previously identified copending application with the improved results obtained by providing narrower slits and the smoother action of the balls 16.

It will be seen that this invention provides a relatively simple, yet highly efiicient, locking mechanism for securely holding a variable gun choke in adjusted position but permitting a uniform shot pattern to be discharged therefrom and also permitting relatively easy adjustment of the choke mechanism.

It will, of course, be understood that various changes may be made in the form, details, arrangement, proportions of the parts, and variations in the number of balls used, without departing from the scope of this invention which, generally stated, consists in the matter shown and described hereinand setv forth in the appended claim.

What is claimed is: A retaining device for adjustable gun chokes of the type havingvan outer rotatable choke sleeve with they forwardtportion tthereof gradually.diminishing in diameter to form a forwardlyitapered camming surface therewithin, an :inner tubular member adapted to be fixed to the forward end 0f:the gun barrel and having the'rear' portion of said sleeve rotatably mounted on an intermediate portion thereofwith the forward portion of said inner tubular member having a plurality.oflongitudinal narrow slits formed therein to produce a plurality of separate choke segments the forward ends of which are generally tapered -to engage the inner tapered camming surface of the sleeve when said sleeve is projected inwardly by said threads xduringrotation thereof, said retaining device comprising va resilient bandsurroundingsaid sleeve at an intermediate hold saidouter sleeve in adjusted position but permitting easy adjustment of the outer sleeve by rotation in either direction.'

References Cited in the file of this patent UNITED STATES PATENTS 2,092,649 i'iun Sept. 7,1937 2,466,104 Hilburn Apr. 5, 1949 2,629,958v Roper et a1. Mar. 3, 1953 

